Concrete bridge.



D. BE LUTBN. CONCRETE BRIDGE. APPLICATION PILPb MAR. 29, 1909.

1,060,920. Patented May 6, '1913.

@yt/venice witness@ I Daniel B. Luie UNITEDl sTATEs PATENT oEEIoE.

i DANIEI. B. LUTEN, or INDIANAroLIs, INDIANA.

CONCRETE BRIDGE.

Original application led November 1,

To all whom t may concern:

Be it known that I, DANIEL B. LUTEN, a citizen of the United States,residing at Indianapolis, in the county of Marion and State of Indiana,have invented certain new` and useful Improvements in Concrete Bridges,of which the following is a specication.

The obj ect of my invention is to produce a concrete structure undersuch conditions that the'loads thereof will be properly sustained and,if there be any cracking it will be along predetermined lines which willneither reduce the strength of the structure nor affect its appearance;to construct an arch structure in successive rings which will besubjected to the stresses of their own weight at different periods inorder that the settling and load stresses in one section o`f arch ringmay be caused' to counteract similar stresses in the adjacent arch ringor spandrel; and to provide such ,improvements in details and methods ofconstruction as shall hereinafter be pointed out.

This application isa division of an appli-- cation filed by me Nov. 1",1906, Serial No. 341,605. Y

The accompanying drawings illustrate my invention.

Figure 1 is a longitudinal vertical section of an arch supported uponits centering. Fig. 2, is a transverse section of an arch showing thepreferred manner of constructing the same'in longitudinal rings.

The abutment or piers 21 are built to about the springing lines s andcentering is erected for one of the'arches at the middle of the axisthereof, the centerinv-being Wide enough to support a ring of reasonablewidth. The concrete is laid upon this centering and, in order that theload of the concrete may be uniformly applied I prefer to place theconcrete simultaneously at the crown and the haunches, depositingconcrete in opposite directions from these points until the entire ringis produced from skewback S to skewback S', thus forming a ring R. Bydepositing the concrete in this way the arch is loaded at the crown andhaunches simultaneously and there is but slight tendency for the ring tobecome distorted. After a ring has been produced the-centering will bestruck, the arch ring thereupon assuming the stresses of its own loadgenerally by sinking slightly at the crown and corre- Specicaton ofLetters Patent.

1906, Serial No. 341,605. Divided and this applic 29.1909. Serial No.486,643. v

Patented May e; 1913.

spondingly rising at the haunches. Two sets of centering may then bearranged at opposite ends of the completed arch ring (see Fig. 2) andadditional arch rings It R are then produced in the same manner, allowedto set, and the centering then withd rawn, the operation being repeatedas many tlmes as may be necessary to complete the span. l

The arches are completed in succession from skewback to skewback in themanner already described, the spandrel walls and the spandrel postsbeing left until the last. The adjacent sections having taken theirsettlement the spandrels will not settle materially and the usual crackswhich occur in the spandrels near the haunches do not appear. After theend rings of the arches are completed the centering maybe eased offbefore the spandrels are completed. A saving in centering may thus beeifected by the repeated use of the centering in the same span.

I claim as my invention:

1. That improvement in the art of building a concrete arch, comprisingerecting on supports an intermediate longitudinal section, permitting itto harden, then lowering the supports under that section, andsubsequently constructing longitudinal sections contiguous to saidintermediate section and on opposite sides' thereof.

2. That improvement in the art of building an arch, comprising erectingon supports an intermediate longitudinal section, per mittiiig it toharden, then lowering the supports under that sect-ion, and subsequentlyconstructing longitudinal sections and bonding them to the firstsect-ions contiguous t0 saidintermediate section and on opposite sidesthereof.

3. That improvement in the art of erecting concrete arches, whichconsists in separately erecting upon supports three contiguous archrings in two set-s, one set comprising two rings and the other setcomprising one ring, one of the sets being allowed to harden and itssupports being removed before the erection of the other set, therebybalancing the eect of one set in its hardened condition against theeffect of the other set.

4. That improvement in the art of building a concrete arch, comprisingerecting on false-work supports an intermediate longitudinal sectionbetween proposed end sections, permitting it to harden, then loweringthe false-Work supports under tht section, and subsequently constructing0n false-Work supports the proposed end sections and bonding them totheintermediate section;

5. Thatmprovelnent in the art of building an arch, comprising erectingon false- Work supports an mtermedate' longitudinal section betweenproposed end sections, then loweringthefalse-Work Supports under thatsection, subsequently constructing 0n falsen work supports'the' proposedend sections and this fifteenth day of ll/Iztrch,l A.l D.

bonding them to the intermediate section, and ereetmg superstructures onsind end sections.

my hand and seal at Indianapolis, Indiana, one thou Copieslof this ptentmay be obtained for ve cents ealch, `by adressing the CommissionerofPlate-ntl, WashingtonLD. C. f

In Witness whereof, I have hereunto set 15

